You have a Facebook profile, right? That's essentially a special-purpose cloud computer - a cloud information appliance. But, wouldn't it be cool to have an actual personal computer in the sky? Where "Facebook" or whatever would just be... a program on that computer?
You can get a Linux box in the sky, easy. But... that's 15 million lines of code you're wrangling. On a network which makes Helm's Deep look like Mayberry.
So, if it's your home in the cloud, it's not a cute little bungalow in the cloud. It's a giant castle in the cloud guarded by experienced professional elf ninja warriors. And ya know, even experienced professional elf ninja warriors, when they're off duty, like to let their hair down and not be thinking about orcs every other minute.
So if you want the bungalow in the cloud, you need basically a new programming/execution environment, and oh also a new network. So basically a new everything. So, a person could despair, or he could go build a new everything...
In the end it compiles down to C, so supposedly any system. Though the virtual machine is bound to have side effects (I/O) so you are bound to whatever platforms they have impleme ted those for, which might as well be Windows XP.
Tldr; this question warrants an answer from someone who knows.